let rec sommeEntier = function 
	| 0 -> 0
	| x -> x + sommeEntier (x - 1)

let main () = 
	if (Array.length Sys.argv) > 1 then
		let x = int_of_string Sys.argv.(1) in
		Printf.printf "val : %d - %d\n" x (sommeEntier x);
		exit 0 
	else 
		invalid_arg "mais t\'es con?"
let _ = main ()
